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