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