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