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