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