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)(13,14,17,19)(15,23,24,20)(16,21,25,27)(18,22,26,28)(5,7,9,8)(6,10,11,12)(14,19)(15,21)(16,23)(18,26)(20,25)(24,27)(1,2,3,4)(13,15,17,24)(14,20,19,23)(16,22,25,28)(18,27,26,21)(5,8,9,7)(6,10,11,12)(13,16)(14,21)(15,22)(17,25)(18,20)(19,27)(23,26)(24,28)(14,19)(15,24)(21,27)(22,28) 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.