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