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