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