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