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