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