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