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