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)(15,20)(16,21)(17,26)(18,22)(19,23)(24,28)(25,27)(2,4)(15,16)(17,18)(20,21)(22,26)(24,25)(27,28) involution — undirected(6,9)(10,12)(13,15)(14,20)(16,17)(18,25)(19,24)(21,26)(22,27)(23,28) involution — undirected(13,16,19,25)(14,21,23,27)(15,17,24,18)(20,26,28,22)(5,7,8,11)(6,10,9,12)(13,17,19,18)(14,22,23,26)(15,16,24,25)(20,27,28,21)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.