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