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