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