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