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