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