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