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