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)(11,23,26,32)(12,27)(13,21)(14,18)(15,19)(16,22)(17,24,34,40)(20,29)(25,36,31,38)(28,35)(30,37,39,33)(9,11,16,26)(10,17,22,34)(12,24,29,40)(13,25,15,31)(14,30,28,39)(18,32,35,23)(19,33,21,37)(20,36,27,38)(1,3,4,8,5,2,6,7)(9,12,15,14,16,29,13,28)(10,18,21,27,22,35,19,20)(11,24,31,30,26,40,25,39)(17,32,37,38,34,23,33,36)(2,3)(7,8)(9,13,16,15)(10,19,22,21)(11,25,26,31)(12,28,29,14)(17,33,34,37)(18,20,35,27)(23,38,32,36)(24,39,40,30)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.