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