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)(15,20,25,28)(16,17,21,18)(23,24,26,27)(2,3)(5,7,8,12)(6,9,10,11)(13,15)(14,20)(16,26)(17,27)(18,24)(19,25)(21,23)(22,28)(1,2,4,3)(6,10)(7,12)(13,16,18,14,19,21,17,22)(15,23,24,28,25,26,27,20)(6,10)(9,11)(13,15)(14,20)(16,26)(17,27)(18,24)(19,25)(21,23)(22,28) involution — undirected(1,3,4,2)(13,17,19,18)(14,21,22,16)(15,24,25,27)(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.