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