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)(11,14,17,21)(12,19,20,15)(18,24,23,22)(25,26)(27,31)(28,35)(29,33)(30,34)(32,36)(37,39)(38,40)(2,5)(6,8)(9,11)(10,14)(12,18)(13,17)(15,22)(16,21)(19,24)(20,23)(25,27,30,33)(26,29,34,31)(28,35,37,39)(32,36,40,38)(11,17)(14,21)(18,23)(22,24)(25,28)(26,32)(27,35)(29,36)(30,37)(31,38)(33,39)(34,40) involution — undirected(9,12,13,20)(10,15,16,19)(11,18,17,23)(14,22,21,24)(25,26)(27,29)(28,32)(30,34)(31,33)(35,36)(37,40)(38,39)(1,3,4,7)(2,6,5,8)(25,29,30,31)(26,33,34,27)(28,36,37,38)(32,39,40,35)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.