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