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