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