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