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