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