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