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