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