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