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