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