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