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