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