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