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