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