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