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