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)(11,19,21,24,20,15,22,23)(25,26)(27,34)(28,32)(29,31)(30,35)(33,37)(36,38)(39,40)(1,2,5,6)(3,7,4,8)(11,20)(15,19)(21,22)(23,24)(25,27)(26,30)(28,35)(29,36)(31,39)(32,34)(33,38)(37,40)(1,3,5,4)(2,7,6,8)(9,11)(10,15)(12,21)(13,22)(14,20)(16,23)(17,19)(18,24)(26,31)(27,35)(29,37)(30,38)(32,33)(34,39)(1,4,5,3)(2,7,6,8)(9,12,14,13)(10,16,17,18)(11,21,20,22)(15,23,19,24)(27,35)(30,34)(36,40)(38,39)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.