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