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