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