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