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