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