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