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