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