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