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