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