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