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