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