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