Our General Regulations state that the badge "is not intended for overt display, but rather is to be worn 'nearest the heart,'" that it "is worn on dress shirts, vests, or pullover sweaters," and "should not be worn on coat lapels, collars, ties, the watch pockets of vests, coat sweaters, or T-shirts."
There are at least two previous threads on this:
Badge Rules?
and
Question for Fraternity Members.