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