The costume consists of a vibrant clown jumpsuit with a neck frill, as well as lesser frills at the wrists and ankles, and black shoes. A clown wig can fit perfectly for the hair, and the face can be painted white. Theater gloves are a good choice for covering the hands, and can be found cheap at Halloween stores during the season. A red balloon or an origami paper boat can make for great accessories to the costume and may give you the touch you need.
A couple or pair of friends can even mix it up by going as both this and the Bill Skarsgard version side-by-side.
As a word of caution, due to a few years worth of "scary clowns" in the media, you may want to wear this costume with an air of caution, as some people may not recognize it as a character and consider you one of the harassment clowns that are occasionally seen throughout the rest of the year.