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