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