One vertex per element, one color per generator, with an edge from x to x·s.
(5,6)(7,15)(8,11)(9,18)(10,14)(12,16)(13,19)(17,20)(21,22)(23,30)(24,28)(25,34)(26,29)(27,32)(31,35)(33,36) involution — undirected(1,2)(3,4)(5,7,9,8,10,16,19,17)(6,11,13,15,14,20,18,12)(2,4)(21,23,25,32,26,33,24,31)(22,27,28,30,29,35,34,36)(5,8,9,16,10,17,19,7)(6,12,13,11,14,15,18,20)(21,24,26,25)(22,28,29,34)(23,31,33,32)(27,30,35,36)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.