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