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