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