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