For a baby, I love it the way it is. I agree that sashing would give up the secondary pattern of the hourglasses. Fandango doesn't need anything to make it pop. I loved the quilt I did for a daughter with it.
Yours is very pretty. I would use a narrow coral border followed by a mid width cream to finish it. You need the coral or aqua to contain all the color. You can find one of the prints online if you want your last border to match. I had the big light coral one and the largest brown, but others were available.