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