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