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