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