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