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