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