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