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