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