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