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