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