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