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