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