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