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