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