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