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