The OP was complaining about clothes being left on the floor, not about having to do the laundry. I do think actually it is ok for her to be annoyed by this. I just would approach it differently with her husband since he's working away during the week and probably comes home pretty tired. I would just be gentle and explain that you need him to still pick up after himself, but maybe there is something else you can do differently as a family to ensure he gets to recover from his work travel over the weekend.
The reason I think it's ok for her to be annoyed is that leaving clothes laying on the floor indicates that even the smallest aspects of tidying up after oneself are beneath one. Think about what it says. "I, the person earning the income, am simply too important to.. pick up my own dirty underwear off the floor. A lesser person should do it." It's disrespectful to the housekeeper, whether the housekeeper is a working wife, a SAHW or a hired housekeeper. Even people who work fulltime should pick up after themselves: put their dirty clothes in the laundry hamper, put their trash in the trash can, scrape their plates into the trash after eating, put their toothbrush in the toothbrush holder, change the empty toilet paper roll, etc. These are just basic aspects of being a person who respects the person who cleans the home.
Even my mother in law told me that my husband needs to pick up his clothes of the floor. That's her son! I think this idea that all SAHWs were just dogsbodies to their husbands is a bit of a myth, actually. My MIL and her sisters and friends all expect their husbands to tidy up after themselves.
In fact, it is extremely difficult to keep a tidy house if everyone doesn't pick up after themselves, because people generate mess on a continuous basis. If the father stops doing it because his work puts him above having to do any tidying up at all, then the children follow, and the mother becomes the lowest person in the household. That is misogynist.
Being the homemaker does not mean that you deserve to be demeaned and that all sh%t work can be palmed off on you.
So I think there needs to be a balance. You can do some nurturing things that accommodate for the fact that working away during the week likely makes him tired. Maybe you can make his favorite meal on Friday nights or make sure his comfy pyjamas are always ready for packing on Sunday afternoons, or refill the travel shampoo containers with the shampoo he likes, or that he has his favorite flavor of granola bars for the train, or that you save episodes of a particular tv show to watch together on the weekend. Little things to make him feel like he's not alone. But he should still pick up his clothes off the floor.