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