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