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