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