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