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