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