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