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