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