One vertex per element, one color per generator, with an edge from x to x·s.
(1,2) involution — undirected(4,6)(7,8)(9,13)(10,20,22,14)(11,23)(12,16)(15,24)(17,25,30,33)(18,31)(19,27)(21,28,35,34)(26,32)(29,37,38,36)(3,4,5,6)(7,9,12,19)(8,13,16,27)(10,17,22,30)(11,18,24,32)(14,25,20,33)(15,26,23,31)(21,29,35,38)(28,36,34,37)(7,10)(8,14)(9,17)(11,21)(12,22)(13,25)(15,28)(16,20)(18,29)(19,30)(23,34)(24,35)(26,36)(27,33)(31,37)(32,38) involution — undirected(7,11,12,24)(8,15,16,23)(9,18,19,32)(10,21,22,35)(13,26,27,31)(14,28,20,34)(17,29,30,38)(25,36,33,37)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.