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