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