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