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