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