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