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