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