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