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