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