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