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