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