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