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