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