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