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