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