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