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