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