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