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