One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,6)(5,8)(9,10)(11,13)(12,14)(15,16)(17,18,21,25,22,26,20,24)(19,23,29,32,27,31,28,30)(1,3,4,8)(2,5,6,7)(9,11,12,15)(10,13,14,16)(17,19)(18,23)(20,28)(21,29)(22,27)(24,30)(25,32)(26,31)(10,14)(11,15)(18,24,26,25)(23,30,31,32)(2,6)(5,7)(19,27)(23,31)(28,29)(30,32) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.