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