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