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