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