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