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