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