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