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