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