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