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