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