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