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