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