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