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