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