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