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