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