Not usually but don't look like you just mucked 6 stalls and bathed 2.
I always changed into khakis and some kid of nice top (you can go buy something). Some tasteful jewelry and an effort with the hair. Clean footwear. Breeches and (clean) boots are acceptable. Jeans and paddocks with a tee shirt? Not so much.
When opportunity knocks it's wearing overalls and looks like work.