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