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