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