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