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