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