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