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