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