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