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