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