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