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