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