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