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