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