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