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