I guess it probably depends on what you believe looking "feminine" is. I haven't had really long hair for all of my life, but I believe I'm feminine. Does it mean wearing makeup all the time or part of the time or wearing frilly dresses all of the time or part of the time.
When I ride my bike, I'm dressed for riding. That means what is practical. To me, that is shorts and a jersey and layers and jackets if need be for colder riding. I don't wear makeup cause it tends to run and look weird afterwards. I don't think I look like a guy when I'm riding. The only time I've ever had trouble telling whether a bike rider was female or male was actually a man with a pony tail who was really skinny!
After riding, and after a shower, riding should not change your look or your femininity. You can dress any way you want, style your hair any way you want or wear as much makeup as you want? I guess I'm just confused about what "Femininity" means to you.