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