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