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