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