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