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