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