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