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