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