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