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