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