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