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