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