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