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