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