One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,5)(6,8)(10,13)(11,15)(14,16)(17,18)(19,25)(20,23)(21,30)(22,27)(24,29)(26,31)(28,32) involution — undirected(2,5)(6,7)(17,19,20,27)(18,22,23,25)(21,26,29,28)(24,31,30,32)(9,10,12,14)(11,16,15,13)(19,26)(21,29)(22,31)(24,30)(25,32)(27,28)(1,3,4,8)(2,6,5,7)(10,14)(13,16)(18,23)(22,25)(24,30)(31,32)A 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.