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