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