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