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