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