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