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