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