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