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