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