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