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