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