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