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