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