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