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