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