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