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