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)(15,20,18,22)(16,17,21,28)(24,25,26,27)(1,2,3,4)(15,18)(20,22)(24,26)(25,27)(5,6,8,9)(7,10,11,12)(13,15,19,18)(14,20,23,22)(16,24,21,26)(17,25,28,27)(5,7,8,11)(6,10,9,12)(13,16)(14,17)(15,24)(18,26)(19,21)(20,25)(22,27)(23,28)(13,17)(14,21)(15,25)(16,23)(18,27)(19,28)(20,26)(22,24) involution — undirected(13,18,19,15)(14,22,23,20)(16,26,21,24)(17,27,28,25)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.