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