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