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