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