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