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