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