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