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)(11,19)(12,21)(13,18)(14,16)(15,20)(17,22)(23,24)(25,26,30,33)(27,28,35,31)(29,32,37,39)(34,36,40,38)(1,3,4,8)(2,5,6,7)(9,11)(10,15)(12,18)(13,17)(14,20)(16,19)(21,23)(22,24)(10,16)(11,20)(17,21)(18,24)(25,27,30,35)(26,31,33,28)(29,34,37,40)(32,38,39,36)(9,11)(10,15)(12,18)(13,17)(14,20)(16,19)(21,23)(22,24)(25,27)(26,28)(29,34)(30,35)(31,33)(32,36)(37,40)(38,39) involution — undirected(9,12,14,22)(10,17,16,21)(11,18,20,24)(13,19,23,15)(25,28)(26,27)(29,36)(30,31)(32,34)(33,35)(37,38)(39,40)(9,13)(10,18)(11,17)(12,15)(14,23)(16,24)(19,22)(20,21)(25,29,30,37)(26,32,33,39)(27,34,35,40)(28,36,31,38)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.