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