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