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