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