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