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