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