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