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