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