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