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