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