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