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