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