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