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