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