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