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