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