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