One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(5,6)(7,12)(8,10)(9,11)(13,14,17,19)(15,18,22,26)(16,20,23,27)(21,25,24,28)(1,2)(3,4)(5,7,9,8)(6,10,11,12)(15,21)(16,23)(18,25)(20,27)(22,24)(26,28)(2,4)(15,22)(18,26)(21,24)(25,28) involution — undirected(2,4)(5,8,9,7)(6,10,11,12)(13,15)(14,18)(16,24)(17,22)(19,26)(20,28)(21,23)(25,27)(6,11)(10,12)(14,19)(18,26)(20,27)(25,28) involution — undirectedA 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.