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