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