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