One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,6)(3,7,8,5)(9,10,13,17,14,18,12,15)(11,19,20,16,22,23,21,24)(25,26)(27,30)(28,32)(29,31)(33,37)(34,39)(35,38)(36,40)(1,3,4,8)(2,5,6,7)(10,15)(12,13)(16,23)(17,18)(19,24)(20,21)(25,27)(26,30)(28,33)(29,35)(31,38)(32,37)(34,36)(39,40)(9,11)(10,16)(12,20)(13,21)(14,22)(15,23)(17,19)(18,24)(27,33)(28,36)(30,37)(32,40)(34,35)(38,39) involution — undirected(9,12,14,13)(10,15,18,17)(11,20,22,21)(16,23,24,19)(26,31)(30,38)(32,40)(37,39)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.