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