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