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