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