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