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