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