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