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