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