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