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