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