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