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