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