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