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