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