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