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