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