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