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