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