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