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