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