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