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