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