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