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