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