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