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