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