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