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