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