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)(13,14,18,19)(15,20,25,24)(16,26,17,21)(22,27,28,23)(6,9)(7,11)(13,15)(14,20)(16,27)(17,23)(18,25)(19,24)(21,22)(26,28) involution — undirected(1,2,3,4)(13,16,18,17)(14,21,19,26)(15,22,25,28)(20,23,24,27)(6,9)(10,12)(13,17,18,16)(14,21,19,26)(15,23,25,27)(20,22,24,28)(5,7,8,11)(6,10,9,12)(14,19)(15,24)(20,25)(21,26)(22,27)(23,28)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.