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