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