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