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