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