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