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