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