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