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