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