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