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