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