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)(11,19)(12,16)(13,14)(15,17)(18,24)(20,23)(21,22)(1,3,5,8)(2,6,4,7)(9,11,15,12)(10,16,17,19)(13,20,24,22)(14,21,18,23)(25,26,30,31)(27,29,33,38)(28,32,37,39)(34,36,35,40)(1,2,5,4)(3,6,8,7)(10,17)(11,12)(14,18)(20,22)(26,31)(29,38)(32,39)(36,40)(1,2,5,4)(3,6,8,7)(9,12,15,11)(10,16,17,19)(13,20,24,22)(14,23,18,21)(25,27,30,33)(26,29,31,38)(28,35,37,34)(32,40,39,36)(1,4,5,2)(3,7,8,6)(9,13)(10,18)(11,20)(12,22)(14,17)(15,24)(16,23)(19,21)(25,28,30,37)(26,32,31,39)(27,34,33,35)(29,36,38,40)(9,14,15,18)(10,13,17,24)(11,21,12,23)(16,20,19,22)(25,29)(26,33)(27,31)(28,36)(30,38)(32,35)(34,39)(37,40)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.