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