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