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