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