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