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