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