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